Lowering device mechanism

ABSTRACT

A lowering device mechanism adapted to be utilized for movement of a structure, such as a luminaire or light-carrying apparatus, from a supported position to an accessible position, the mechanism having novel structural features permitting the simplified and efficient lowering or raising of the apparatus, for servicing, repairing, or replacing elements of the apparatus as necessary.

United States Patent Inventor Henry C. Pfaff, Jr.

Summit, NJ.

Appl. No. 798,247

Filed Jan. 21, 1969 Patented Oct. 5, 1971 Assignee Piaif and Kendall Newark, NJ.

LOWERING DEVICE MECHANISM 5 Claims, 6 Drawing Figs.

U.S. Cl 254/173, 240/66, 248/320, 254/168 Int. Cl 866d 1/48 Field of Search 254/168,

[56] References Cited UNITED STATES PATENTS 1,490,671 4/1924 Lindstrom et a] 254/]68 2,609,170 9/1952 Farrington et al. 240/66 3,355,149 11/1967 Wiegelmann et al. 254/173 Primary Examiner-Evon C. Blunk Assistant Examiner-Alfred N. Goodman Attorney-Sommers & Sommers ABSTRACT: A lowering device mechanism adapted to be utilized for movement of a structure, such as a luminaire or light-carrying apparatus, from a supported position to an accessible position, the mechanism having novel structural features permitting the simplified and efficient lowering or raising of the apparatus, for servicing, repairing, or replacing elements of the apparatus as necessary.

SHEET 2 BF 4 FIC5.2

INVENTOR H. C. PFAFF. JR.

PATENTED um 51% SHEET 3 0F 4 FIG. 4

INVENTOR H. C. PFAFF'. JR

ATTORNEYS PATENTEU 11131 5 W1 SHEET k [1F 4 INVENTOR H. C. PFAFF. JR

ATTORNEYS LOWERING DEVICE MECHANISM This invention relates to a lowering device mechanism, providing access to apparatus to be supported at a remote or inaccessible position, for servicing, repairing or replacing elements thereof, and more particularly to a lowering mechanism adapted to be utilized in conjunction with a lighting fixture or luminaire unit, to enable access for replacement of lamps and cleaning of component parts thereof.

Pursuant to the invention, the lowering device mechanism may be lowered or raised automatically, in a simplified, safe and efficient fashion, with means thereon to minimize rotational movement, to provide support, and to automatically stop the apparatus carrying portion while same is being raised or lowered, and with means to afford further safety in the supported position of the apparatus and to selectively open and close the circuit to the fixture in a smooth and positive fashion.

Devices proposed for this purpose heretofore have generally been objectionable due to their complexity and high cost of manufacture, requirement for substantial maintenance danger and inefficiency due to swinging in lowering and elevating movements the apparatus, and were hazardous to safety in malfunction and breakage of the apparatus.

These and other objections to devices heretofore proposed, have been eliminated in the lowering device mechanism of this invention, which is rugged, durable, efficient and safe in use.

In the drawings, wherein similar reference characters indicate like parts:

FIG. 1 is a side elevational, partly broken view of a lowering device mechanism embodying the invention, taken on line 1- 1 of FIG. 2,

FIG. 2 is a front elevational, partly broken view thereof, taken at line 2-2 of FIG. 1,

FIG. 3 is a fragmentary, sectional, elevational view of a safety mechanism which may be used in connection with the invention,

FIG. 4 is a bottom plan view thereof, taken on line 4-4 of FIG. 1,

FIG. 5 is a top plan, partly broken view, taken on line 5-5 of FIG. 1, and

FIG. 6 is a horizontal, sectional view, taken on line 66 of FIG. 2.

As will be seen from the drawings, forming a part hereof, this invention relates to a lowering device mechanism operating, as will be described below with reference generally to FIGS. 1 and 2, so that the lower body member may be lowered or raised for selective opening and closure with the upper body member by a lowering means operated by drive means and stopped by braking means, and having therein a novel safety catch mechanism.

The lowering device mechanism 11 (FIGS. 1 and 2) for example, consists of an upper body member 12, a lower body member 13, lowering means 14, drive means 15, and brake means 16.

The upper body member 12 is mounted on a ceiling or other supporting surface at the top portion T thereof, for example, and houses portions of the operational sections of the mechanism. The lower body member 13 has attached to the base B thereof, an apparatus such as a lighting fixture or luminaire, which is to be lowered from a position adjacent the ceiling or supporting surface, for access thereto.

The lowering means 14 and 14' (FIG. 2), for example, may comprise a pair of matched systems, each of which comprises (referring to lowering means 14, FIG. I) a'drum 42, and a flexible ribbon 43 (of stainless steel, for example) which is wrapped around the drum 42 and is threaded between the directional roller 44 (rotatably seated on shaft 65) and the eutoil roller 41 of cutoff switch 45, and said tape (FIG. 1) is secured by suitable means such as, for example, screw means 46, to the connection member 47, which, in turn, is secured to lower body member 13 as at 50 (FIG. 2). Two or more sets of poles consisting of upper contacts 51 and lower contacts 52, provide electrical power through the lowering device to the luminaire or other power-requiring apparatus attached to the lowering device when it is in the fully raised position.

The drive means 15 (FIGS. 1 and 2) consists of a drive motor 31 with drive shaft 32 extending therethrough and driven thereby, a drive sprocket 33 keyed to drive shaft 32, roller chain 34, entrained over drive sprocket 33 and worm shaft sprocket 35, the latter keyed to worm shaft 36 having worm 37. Worm 37 (FIG. 2) meshes with the worm gear 38 to thereby drive the drum shaft 39 which drives the lowering means 14 and 14'.

The brake means 16, for example, (FIG. 1) consists of a brake solenoid 21 which operates on an electrical impulse from means such as a master switch (not shown) to control retention or release of the lower portion 26 of the brake lever arm 22, thereby closing (on release) or opening (on retention) the brake jaws 24 and 24' with respect to the brake disc 23. The brake compression spring 25 normally presses against the brake lever arm 22 (Pivoted at 27, FIG. I) causing the brake jaws 24 and 24' to be normally closed on the brake disc 23. The action of the brake solenoid 21 on retaining the lower portion 26 to open the brake jaws 24 and 24' is in opposition to the brake compression spring 25.

An automatic down stop is built into the unit to prevent overtravel, in the form of automatic stop means 17, which consists of cutoff switch 45 activated on interruption of a circuit on passage of that portion of tape 43 having a prepositioned aperture h between the directional roller 44 and the eutoff roller 41; the current to the motor 31 and the brake solenoid 18 is then cut off.

A safety mechanism 61 may be provided (FIG. 3) consisting of a latch 62 turning on shaft 65, said shaft being operated by solenoid 63 to move latch 62 into or out of hooking relationship with U-bolt 64 secured to lower body member 13 and thereby preventing accidental disengagement of the latter.

In operation (FIGS. 1 and 2) the top T of upper body member 12 is fixed to a ceiling or other supporting surface, the lower body member 13 being movable relative thereto into and out of electrical and physical connection, by operation of the lowering means 14 on activation of the drive means 15 and release of the brake means 16. The downward movement of the lower body member 13, with a luminaire or other lighting apparatus attached to the base B thereof (FIGS. 1 and 2) can be stopped at a desired point by operation of the brake means 16 or the automatic stop means.

If it is desired to lower the apparatus in order to obtain access thereto, a master switch (which may be located on a wall, control panel or other position, not shown) is moved to one position, to thereby activate the solenoid 21 to retain the lever arm 22 and open the jaws 24 and 24', thereby releasing the brake means 16 and to also release and activate the drive means 15. Drive shaft 32 rotates and turns the drive sprocket 33 and thereby drives the roller chain 34 and worm shaft sprocket 35 in turn, rotation of the worm shaft sprocket 35 rotates worm gear shaft 36 and worm 37. Worm 37 meshes with the worm gear 38 (FIG. 2) driving the latter on shaft 39, moving the lowering means 14 therewith. There are (FIG. 2) two sets of identical lowering means 14 and 14' on opposite sides of the upper body. The number of units l4, 14' could be increased if desired and instead of flat form, they may be of other cross-sectional contour. The use of a pair of flexible steel cables or tapes has been found highly satisfactory and is shown and described by way of example. For convenience, reference will be made to lowering means 14. As drum 42 rotates, it unwinds the flexible ribbon 43 which passes between roller 44 and sensing cutoff roller 41. Flexible ribbon 43 is connected to the lower body member 13 by means such as connection member 47 and bolt means 46 (FIG. 1). Unwinding of the cable 43 from drum 42 causes lowering of the body member 13 out of engagement with upper body member 12. This lowering movement continues until a stop button is pressed on the master switch, thereby deactivating the drive motor 31 and the solenoid 21, whereupon the lever arm 22 rotates on pivot 27 counterclockwise responsive to compression spring 25; the solenoid core 18 moves outwardly and the brake jaws 24 and 24' clamp on the brake disc 23, stopping further rotation of the drive shaft 32. Automatic stop means operative on opening the circuit, for example, may comprise an aperture A (FIG. 6) formed in flexible ribbon 43 at a predetermined point along its length so that, when the so apertured portion of flexible ribbon 43 is disposed between the directional roller 44 and the cutoff roller 41, at said predetermined point, opening, through switch 45 controlling solenoid 21, the electrical circuit for solenoid 2l, whereupon the brake jaws 24 and 24' will clamp on the brake disc 23, stopping the downward movement of the lowering means 14. The aligned tape lowering means 14 and 114' assure direct vertical movement of the lower body member 13 on ascent and descent.

After repair or replacement of the luminaire or apparatus mounted on the base B of the lower body member 13, the lower body member 13 may be raised by turning the switch button on the master switch to the proper position to activate motor drive means 15 for rotation in the desired direction to thereby rotate drive shaft 32 and elevate the apparatus and activate the brake solenoid 21, compressing spring 25 and opening brake jaws 24, 24' and thereby releasing the brake disc 23. Rotation of the drive means 15 causes the drum 42 to wind the flexible ribbon 43, thereby raising the lower body member 13 toward the upper body member 12. Just prior to the physical connection of the lower body member with the upper body member, the lower ground contacts 52 will touch with the upper spring loaded contacts 51 to thereby ground the electrical apparatus to prevent electrical arcing; further upward motion works against pressure from the spring 55 to thereby ease the force of upward progress until the lower circuit contacts 54 contact with the upper circuit contacts 53, thereby completing the electrical circuit and permitting the illumination of the luminaire or lighting apparatus in a normal functioning manner.

On final physical closure of the lower and upper body member the safety mechanism 61 operates (FIG. 3); as the solenoid 63 is deenergized, this permits the latch 62 to move into hooking relationship with the U-bolt 64. Should the cables 43 break while the mechanism is in a raised position, the safety mechanism 61 is hooked tightly in place and will prevent the lower body member 13 from falling and injuring persons walking below.

The lowering device mechanism of my invention will be durable and long lasting in use, will provide a firm and strong support for the load or apparatus to be carried on the lower body member, and will prevent possible injury to persons gathered within the area of use of the device.

While the foregoing disclosure of exemplary embodiments is made in accordance with the Patent Statutes, it is to be understood that the invention is not to be limited thereto or thereby, the inventive scope being defined in the appended claims.

lclaim:

l. A lowering device mechanism, for lowering or raising an elevated mounted electrical fixture, comprising:

a. an upper body member to be supported in a raised or elevated position,

b. a lower body member, movably connected to said upper body member,

c. lowering means, positioned in said upper body member and interconnected with said lower body member for relative movement of said lower body member with respect to said upper body member,

d. said lowering means including a drum,

e. a flat ribbon wrapped around said drum and connected with said lower body member, and

f. a reversible electric motor having a shaft operably connected with said drum;

g. brake means for braking said lowering means and including a brake disc fixed on the electric motor shaft,

h. a pivotally mounted brake lever arm,

i. a pair of brake jaws extending from one end of the brake lever arm and disposed on either side of said brake disc,

j. a brake solenoid connected with the other end of said brake lever arm for pivoting the arm and releasing said brake jaws to said brake disc when actuated, k. a spring means acting on said brake lever arm urging it toward the brake applying position,

I. and an electric switch operably connected with said electric motor and with said brake solenoid,

m. said electric switch having an actuator engageable with said flat ribbon, and

n. control means carried by said flat ribbon for actuating said switch to interrupt the supply of electric current to said electric motor and to simultaneously deactuate said brake solenoid.

2. A lowering device mechanism as described in claim 1 in which said control means comprises an opening formed in said flat ribbon for receiving therein the actuator for the electric switch.

3. A lowering device mechanism as described in claim 1 in which said upper body member carries upper ground contacts and upper circuit contacts for supplying current to the electrical fixture, and said lower body member carries lower ground contacts and lower circuit contacts, and said upper and lower ground contacts make contact as the lower body member is moved to the fully raised position prior to the time said upper and lower circuit contacts make contact.

4. A lowering device mechanism as described in claim 3 in which one of said upper ground contact and said lower ground contact is resiliently mounted for movement toward and away from the other ground contact.

5. A lowering device mechanism as described in claim 1 including a safety latch for maintaining the lower body member in the raised position, said safety latch comprising a safety bolt connected to said lower body member, a safety latch movably mounted on the upper body member and normally engaged with said safety bolt, and a solenoid connected with said safety latch and operably for disengaging said safety latch from said safety bolt. 

1. A lowering device mechanism, for lowering or raising an elevated mounted electrical fixture, comprising: a. an upper body member to be supported in a raised or elevated position, b. a lower body member, movably connected to said upper body member, c. lowering means, positioned in said upper body member and interconnected with said lower body member for relative movement of said lower body member with respect to said upper body member, d. said lowering means including a drum, e. a flat ribbon wrapped around said drum and connected with said lower body member, and f. a reversible electric motor having a shaft operably connected with said drum; g. brake means for braking said lowering means and including a brake disc fixed on the electric motor shaft, h. a pivotally mounted brake lever arm, i. a pair of brake jaws extending from one end of the brake lever arm and disposed on either side of said brake disc, j. a brake solenoid connected with the other end of said brake lever arm for pivoting the arm and releasing said brake jaws to said brake disc when actuated, k. a spring means acting on said brake lever arm urging it toward the brake applying position, l. and an electric switch operably connected with said electric motor and with said brake solenoid, m. said electric switch having an actuator engageable with said flat ribbon, and n. control means carried by said flat ribbon for actuating said switch to interrupt the supply of electric current to said electric motor and to simultaneously deactuate said brake solenoid.
 2. A lowering device mechanism as described in claim 1 in which said control means comprises an opening formed in said flat ribbon for receiving therein the actuator for the electric switch.
 3. A lowering device mechanism as described in claim 1 in which said upper body member carries upper ground contacts and upper circuit contacts for supplying current to the electrical fixture, and said lower body member carries lower ground contacts and lower circuit contacts, and said upper and lower ground contacts make contact as the lower body member is moved to the fully raised position prior to the time said upper and lower circuit contacts make contact.
 4. A lowering device mechanism as described in claim 3 in which one of said upper ground contact and said lower ground contact is resiliently mounted for movement toward and away from the other ground contact.
 5. A lowering device mechanism as described in claim 1 including a safety latch for maintaining the lower body member in the raised position, said safety latch comprising a safety bolt connected to said lower body member, a safety latch movably mounted on the upper body member and normally engaged with said safety bolt, and a solenoid connected with said safety latch and operably for disengaging said safety latch from said safety bolt. 